Community configuration introduces an alternative config interface, which either fallbacks to MainConfig (when the requested config option is not managed by CommunityConfiguration) or loads a JSON blob from a wikipage (when the requested config option is managed by CommunityConfiguration), which is then used to determine the config option's value.

Even though we cache the wikipage after we load it, it is still a potentially expensive operation, that might go wrong. Since CommunityConfiguration is designed to be a hard dependency for its client extensions, we need to provide a way to disable anything potentially expensive in CommunityConfiguration.

This can be done by adding wgCommunityConfigurationEmergencyShutdown to MediaWiki-extensions-CommunityConfiguration, which would short-circuit MediaWikiConfigReader (the access class). That should make it possible to cut off all potentially dangerous codepaths, making it possible for us to shutoff all potentially dangerous codepaths in CommunityConfiguration.